Holding device for holding cooling fan

ABSTRACT

A holding device for holding a cooling fan comprising: a duct having a hollow in which a cooling fan is to be fitted; a stopper portion which keeps one operative end of the cooling fan from further moving to hold the cooling fan at a fitting position; and a plurality of elastic wall segments formed in a cooling fan insertion end of a wall of the duct; wherein each of some of the plurality of elastic wall segments is formed with a locking claw for keeping the other operative end of the cooling fan from moving. With this construction, the cooling fan 31 can be more surely mounted in a duct. Consequently, vibration reduction effect and sound reduction effect with respect to the cooling fan is improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a holding device for holding a coolingfan.

2. Description of the Related Art

In a conventional holding device for holding a cooling fan, as describedin Japanese Unexamined Patent Publication No. 2000-172031, a cooling fanis fitted into a cylindrical member which is molded of an elasticmember, such as rubber, and is fixed by screws.

In the holding device for holding a cooling fan of the prior art, acooling fan is held by an elastic cylindrical member to enhance thevibration reduction effect and sound reduction effect.

However, the holding device of Japanese Unexamined Patent PublicationNo. 2000-172031 requires use of an elastic cylindrical member, e.g.,made of rubber, as a duct. Further, the cooling fan is required to befixed to the elastic cylindrical member by screws. Consequently, thereis the problem that the part cost and assembling cost rise.

SUMMARY OF THE INVENTION

The present invention has worked out in view of the problems describedabove, and an object of the invention is to provide a holding device forholding a cooling fan which requires less cost for parts and assemblingand is high in the vibration and sound reduction effects.

According to an aspect of the present invention, a holding device forholding a cooling fan comprises: a duct having a hollow in which acooling fan is to be fitted; a stopper portion which keeps one operativeend of the cooling fan from further moving to hold the cooling fan at afitting position; and a plurality of elastic wall segments formed in acooling fan insertion end of a wall of the duct, wherein each of some ofthe plurality of elastic wall segments is formed with a locking claw forkeeping-the other operative end of the cooling fan from moving.

With this construction, when the cooling fan is fitted into the duct,one operative end of the cooling fan is kept from moving by the stopperportion and the other operative end of the cooling fan is kept frommoving by the locking claw formed on an elastic segment. Consequently,the cooling fan is assuredly attached to the duct, which therebyincreases the vibration reduction effect and the sound reduction effectwith respect to the cooling fan.

These and other objects, features, aspects, and advantages of thepresent invention will become more apparent from the following detaileddescription of the preferred embodiments/examples with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view showing an image forming apparatusaccording to an embodiment of the invention.

FIG. 2 is a perspective view showing a metal frame on which a holdingdevice holding a cooling fan is mounted.

FIG. 3A is a perspective view showing the cooling fan.

FIG. 3B is a perspective view showing the holding device in which thecooling fan is to be fitted.

FIG. 4A is a perspective view showing the holding device.

FIG. 4B is a plan view showing the holding device.

FIG. 5A is a cross-sectional view showing the holding device.

FIG. 5B is a cross-sectional view showing relevant parts of the holdingdevice and the cooling fan.

FIGS. 6A and 6B are perspective views showing steps of mounting theholding device to the metal frame.

FIG. 7 is a perspective view showing a modified holding device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, in a box-shaped main body 2 of a printer 1, that isone of image forming apparatuses, a charging device 3 charges uniformlya peripheral surface of a photoconductive drum 4 which rotates in adirection A as shown in FIG. 1. An exposing portion 5 irradiates a laserlight ray B based on an image data to the peripheral surface of thephotoconductive drum 4 to form an electrostatic latent image. Adeveloping device 6 supplies toner to the electrostatic latent imageformed on the photoconductive drum 4. Consequently, a toner image isformed on the peripheral surface of the photoconductive drum 4.

A paper sheet P is conveyed from a paper feeding mechanism 8 to thephotoconductive drum 4. A transferring roller (a transferring device) 9transfers the toner image formed on the surface of the photoconductivedrum 4 to a surface (transferred surface) of the paper sheet P. Afterthe transfer of the toner image is completed, a cleaning device 11including a cleaning roller 10 removes the toner left on thephotoconductive drum 4. Then, a charge removing device 12 removes aresidual electric charge left on the photoconductive drum 4.

Then, the paper sheet P which is separated from the photoconductive drum4 by a separating device 13 is conveyed to a pair of fixing rollers(fixing device) 14. The toner image is fixed on the paper sheet P by thefixing roller pair 14, and then the paper sheet P is directly (or afterbeing turned over by an unillustrated switch back device for adouble-face printing) discharged to a discharging portion 16 by adischarging roller 15.

The paper feeding mechanism 8 includes a paper feeding cassette 20 whichis detachably mounted on the printer main body 2, and stores a number ofpaper sheets P being stacked. This paper feeding cassette 20 includes apickup roller 21 for picking up a stored paper sheet P. The paperfeeding cassette 20 also includes a paper feeding roller 22 for feedinga paper sheet P picked up by the pickup roller 21 to a conveyancepassage each picking. At the upstream (on the right hand side in FIG. 1)of the photoconductive drum 4 in the conveyance passage, a pair ofregistration rollers 23 for holding the paper sheet P transferred fromthe paper feeding roller 22 is mounted.

The conveyance passage further includes a first conveyance passage 25for conveying the paper sheet P from the paper feeding cassette 20 tothe photoconductive drum 4, a second conveyance passage 26 for conveyingthe paper sheet P from the photoconductive drum 4 to the fixing rollerpair 14, and a third conveyance passage 27 for conveying the paper sheetP from the fixing roller pair 14 to the discharging roller 15.

A cooling fan 31 is mounted on a metal frame 30 (shown in FIG. 2) of theprinter main body 2. As indicated by the double-dotted chain line inFIG. 1, the cooling fan 31 is mounted at a portion of the metal frame 30in the half side where the fixing roller pair (fixing device) 14 isprovided. Further, though it is not specifically illustrated, the metalframe 30 has an opening for taking in an outer air. The cooling fan 31takes outer air into the printer main body 2 through the opening.

The fixing roller pair (fixing device) 14 has a heat generative body.Near the fixing roller pair (fixing device) 14, a polygon motor, whichhas also a heat generative body, is provided. The cooling fan 31generates an air flow which is taken in to cool the heat generativebodies.

The cooling fan 31 includes a rectangular-shaped fan main body 31 a. Asshown in FIG. 3A, in a center portion of the fan main body 31 a, a fanwhich is to be driven by an electric motor is provided. Electricity issupplied to the electric motor by a connector 31 b through a lead wire31 c.

As shown in FIG. 3B, the cooling fan 31 is fitted into a holding device33 made of a plastic resin and held on the holding device 33.

As shown in FIGS. 4A and 4B, the holding device 33 has a cross sectionof a rectangle. At each of four corners of four side wall portions(duct) 33 a, a stopper portion 33 b which keeps each corner of a lowerend (one operative end) of the fan main body 31 a of the cooling fan 31from further moving to hold the cooling fan 31 at an attachmentposition.

Each of the four side wall portions 33 a of the holding device 33 has aplurality of slits 33 c (four slits in this embodiment) formed in acooling fan insertion end. The slits 33 c define a plurality of elasticwall segments 33 d (three segments in this embodiment). The slits enableeach of the elastic wall segments 33 d to be elastically bent inward andoutward with respect to a hollow of the holding device 33.

As shown in FIG. 5A, among the elastic wall segments 33 d formed in eachof the four side wall portions 33 a, each of the elastic wall segments33 d located at center of each side is formed with a locking claw 33 efor keeping the upper end (other operative end) of the cooling fan mainbody 31 a from moving while the stopper portions 33 b of the holdingdevice 33 keep the lower end (one operative end) of the fan main body 31from moving.

Further, among the plurality of elastic wall segments 33 d formed ineach of the four side wall portions 33 a, each of the elastic wallsegments 33 d located adjacent to the elastic wall segment 33 d (otherelastic wall segments) is formed with a projection 33 f which presses aside surface (a side surface between the operative ends) of the coolingfan main body 31 a of the cooling fan 31 inward.

As specifically shown in FIG. 5B, each of the projection 33 f includes aslanting surface 33 g which comes into contact with an upper side edgeportion 31 3 of the fan main body 31 a of the cooling fan 31 forpressing the cooling fan 31 toward the stopper portion 33 b and/orinward.

At each of the four ends of the bottoms of the opposite left and rightwall portions of the holding device 33, an L-shaped inserting claw (anattachment flange) 33 j is formed. The L-shaped inserting claw 33 jextends from the bottom of the holding device 33 in an axial direction,and then extends in a laterally outward direction at the distance fromthe bottom that corresponds to a thickness of the metal frame 30.Further, between the two inserting nails 33 j on each of the left andright sides is formed a flange extending laterally outward from the sidesurface of the holding device 33, the flange being formed with a boss 33k on the bottom surface thereof.

As shown in FIG. 6A, openings each having a window 30 a and a slitportion 30 b are formed in the metal frame 30. The openings respectivelycorrespond to the inserting claws 33 j of the holding device 33. Thewindows 30 a allow the inserting claws 33 j to pass laterally. The slitportion 30 b extends downward from the window 30 a.

Further, the metal frame 30 is formed with fixing holes 30 c forretaining the bosses 33 k respectively correspondingly to the bosses 33k.

If each of the inserting claws 33 j of the holding device 33 is passedthrough the window portion 30 a of the metal frame 30 laterally, and isslid downward along the slit portions 30 b as shown in FIG. 6B, each ofthe inserting claws 33 j comes in contact with the lower edges of theslit portion 30 b. Consequently, the holding device 33 is fixedly heldto thereby keep the holding device 33 from moving in the forward andbackward directions, the left and right directions, and the downwarddirection.

At the same time, the bosses 33 k are placed in the fixing holes 30 c tothereby keep the holding device 33 from moving in the upward direction.

In this way, the holding device 33 can be easily attached to the metalframe 30 with one-touch operation.

As described above, with the holding device for holding the cooling fanof the image forming apparatus, when the cooling fan 31 is fitted intothe holding device 33, the lower end of the fan main body 31 a of thecooling fan 31 comes in contact with the stopper portions 33 b, and isthereby kept from further moving downward. The upper end of the mainbody 31 a of the cooling fan 31 is locked by the locking claws 33 e oneach of the central elastic segments 33 d. At the same time, the sidewall portions of the main body 31 a of the cooling fan 31 is pressedinward from four directions by the projections 33 f of the elasticsegments 33 d on the opposite sides.

Accordingly, since the cooling fan 31 is assuredly mounted in theholding device 33, the vibration reduction effect and the soundreduction effect with respect to the cooling fan 31 can be increased.

Further, the holding device does not require use of an elasticcylindrical body, e.g., made of rubber, as the holding device 33, andthe holding device 33 can be made of an inexpensive plastic resinmaterial. Furthermore, the cooling fan 31 can be easily mounted in theholding device 33 with one-touch operation in the attachment operation.Consequently, the costs for parts and assembling can be considerablyreduced.

Furthermore, since the slanting surface 33 g which presses the upperside edge portion 31 3 of the main body 31 a of the cooling fan 31inward or toward the stopper portion 33 b is formed on each of theprojections 33 f of the elastic segments 33 d, the upper side edgeportion 31 3 of the cooling fan 31 is pressed toward the stopper portion33 b. Consequently, the cooling fan 31 can be more assuredly mounted inthe holding device 33.

Furthermore, as shown in FIG. 3B, a lead wire 31 c of an electric motorof the cooling fan 31 can be efficiently arranged utilizing one of theslits 33 c formed in the holding device 33.

According to the embodiment, a plurality of (three in the embodiment)the elastic segment 33 d is formed on each of the four side wallportions 33 a of the holding device 33. However, as shown in FIG. 7, asingle elastic segment 33 d formed with a locking claw 33 e andprojections 33 f may be formed in each of the four side wall portions 33a.

According to the embodiment, the cooling fan 31 is fitted and fixed inthe holding device 33 having the cross-section of a rectangle. However,it may be appreciated to use a holding device 33 having thecross-section of a polygon other than a rectangle, or the cross-sectionof a circle. The cross-section of an outer casing of the cooling fan 31may be formed so as to be in conformity with the inner shape of theholding device 33.

The foregoing embodiment refers to the holding device for holding acooling fan 31 that is attached in an image forming apparatus. However,it goes without saying that the present invention can be applied to anapparatus other than an image forming apparatus.

As described above, a holding device for holding a cooling fancomprises: a duct having a hollow in which a cooling fan is to befitted; a stopper portion which keeps one operative end of the coolingfan from further moving to hold the cooling fan at a fitting position;and a plurality of elastic wall segments formed in a cooling faninsertion end of a wall of the duct. Each of some of the plurality ofelastic wall segments is formed with a locking claw for keeping theother operative end of the cooling fan from moving.

With this construction, when the cooling fan is fitted in the duct, theone operative end of the cooling fan is kept from further moving by thestopper portion, and the other operative end of the cooling fan islocked by the locking claw formed on each of some of the elasticsegments. Accordingly, the cooling fan can be assuredly mounted on theduct. Consequently, the vibration reduction and the sound reductioneffect with respect to the cooling fan can be enhanced. Further, theholding device does not require the use of a cylindrical elastic body,e.g., made of rubber, as the holding device. The holding device can bemade of an inexpensive plastic resin material. In accordance with thefitting operation, the cooling fan 31 can be locked onto the holdingdevice with one-touch operation. Consequently, the costs for parts andassembling can be reduced.

Further, it may be preferable that each of the other elastic wallsegments is formed with a projection which presses the cooling faninward. With this construction, the cooling fan is pressed inward.Accordingly, the cooling fan can be more surely mounted in the duct.

It may be preferable that the duct has a cross section of a rectangle,and four wall segments formed with the projection are arranged on thefour sides of the duct, respectively. With this construction, thecooling fan is pressed from four opposite sides. Consequently, thecooling fan can be more surely held in the duct.

It may be preferable that the projection includes a slanting surface tocome into contact with a side edge of the cooling fan for pressing thecooling fan toward the stopper portion. With this construction, theprojection and the stopper portion cooperates to hold the cooling fan.Consequently, the vibration reduction and the sound reduction effect canbe increased.

It may be preferable that each of the predetermined elastic segments isformed with a projection for pressing which presses the cooling faninward. With this construction, the cooling fan is pressed inward.Consequently, the cooling fan can be more surely mounted in the duct.

It may be preferable that the elastic segment is defined by slits formedin the cooling fan insertion end of the wall of the duct. With thisconstruction, the elastic segments can be easily formed by formingslits.

It may be preferable that a lead wire of an electric motor of thecooling fan is passed through the slit. With this construction, a leadwire of the electric motor can be efficiently placed.

In the case where the holding device is mounted on an image formingapparatus provided with a frame member formed with attachment holes andfixing holes, it may be preferable to form an attachment flange on eachof respective attachment edges of the opposite side walls of the ductfor retaining the duct to the frame member in a state of being passedthrough the attachment holes and a boss on each of the respectiveattachment end edges of the opposite walls of the duct for keeping theduct from moving in a state of being placed in the fixing hole. Withthis construction, a holding device in which a cooling fan is mountedcan be more surely mounted on the frame member of the image formingapparatus.

This application is based on patent application No. 2005-124970 filed inJapan, the contents of which are hereby incorporated by references.

As this invention may be embodied in several forms without departingfrom the spirit of essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, since thescope of the invention is defined by the appended claims rather than bythe description preceding them, and all changes that fall within metesand bounds of the claims, or equivalence of such metes and bounds aretherefore intended to embraced by the claims.

1. A holding device for holding a cooling fan comprising: a duct havinga hollow in which a cooling fan is to be fitted; a stopper portion whichkeeps one operative end of the cooling fan from further moving to holdthe cooling fan at a fitting position; a plurality of elastic wallsegments formed in a cooling fan insertion end of a wall of the duct;wherein each of some of the plurality of elastic wall segments is formedwith a locking claw for keeping the other operative end of the coolingfan from moving.
 2. A holding device for holding a cooling fan accordingto claim 1, wherein each of other elastic wall segments is formed with aprojection which presses the cooling fan inward.
 3. A holding device forholding a cooling fan according to claim 2, wherein the duct has a crosssection of a rectangle, and wall segments formed with the projection arearranged on the four sides of the duct, respectively.
 4. A holdingdevice for holding a cooling fan according to claim 2, wherein theprojection includes a slanting surface to come into contact with a sideedge of the cooling fan for pressing the cooling fan toward the stopperportion.
 5. A holding device for holding a cooling fan according toclaim 1, wherein each of predetermined elastic wall segments is formedwith a projection which presses a side between the opposite operativeends of the cooling fan inward.
 6. A holding device for holding acooling fan according to claim 5, wherein the projection includes aslanting surface to come into contact with a side edge of the coolingfan for pressing the cooling fan toward the stopper portion.
 7. Aholding device for holding a cooling fan according to claim 1, whereinthe elastic wall segment is defined by slits formed in the cooling faninsertion end of the wall of the duct.
 8. A holding device for holding acooling fan according to claim 7, wherein a lead wire of an electricmotor of the cooling fan is passed-through the slit.
 9. A holding devicefor holding a cooling fan according to claim 1, wherein the device is tobe attached in an image forming apparatus.
 10. A holding device forholding a cooling fan according to claim 9, wherein the device is to beattached on a frame member provided in the image forming apparatus, andthe frame member is formed with attachment holes and fixing holes,further comprising: an attachment flange formed on each of respectiveattachment end edges of the opposite walls of the duct for retaining theduct to the frame member in a state of being passed through theattachment holes; and a boss formed on each of the respective attachmentend edges of the opposite walls of the duct for keeping the duct frommoving in a state of being placed in the fixing hole.